Recent studies have shown that a partially purified, cartilage-derived growth factor (CDGF) promotes neovascularization of granuloma tissue and is mitogenic for microvascular endothelial cells. The proposed pilot study will analyze the action of CDGF on cultured microvascular endothelial cells. Biochemical measuremtns will focus on (1) the synthesis and degradation of several collagen types found in the medium and cell layer and (2) cyclic AMP production. The availability of specific immunological probes for collagen types I, III, IV and V will allow us to examine the synthesis of individual collagen types by enzyme-linked immunoadsorbant assay (ELISA) techniques. The ability of interstitial collagens (types I and III) and basement membrane proteins (collagen types IV and V, laminin and fibronectin) to modulate CDGF stimulation of microvascular endothelial cell collagen metabolism will also be examined. The effect of CDGF on secretion of a latent collagenase for interstitial collagens and stimulation of cellular degradation of basement membrane collagens will be studied. This research will test the hypothesis that some CDGF actions are mediated by an increase in cyclic AMP production. These studies will include the effect of CDGF on production of prostaglandins E2 and I2 which are recognized to increase cyclic AMP in microvascular endothelial cells. The ultimate goal of the project is to elucidate the actions of CDFG on capillary endothelial cells in vitro and subsequently neovascularization and wound repair in vivo